WildlifePlumes of PoisonThe New Guinea pitohui is one of few bird species whose feathers and skin are poisonous. The researcher who studied these birds and discovered the source of their toxicity recounts his experience—and reveals what could happen if that source were to disappear.By Kristin Elise Phillips

A hooded pitohui.

John Dumbacher

We Boiled 10 Parokeets to night for Dash who has had 10 Welps—purposely to try the effect of the Poisoning effect of their hearts on animals. Yesterday We Were told that 7 Cats had been Killed Last Summer by Eating as Many Parokeets.—John James Audubon, December 29, 1820

These aren’t the most famous words that John James Audubon wrote, nor is there a painting to illustrate this scene. But his dog Dash was never again mentioned in his journal, and some historians believe that Audubon learned the hard way that the Carolina parakeet could be poisonous.

Toxic birds aren’t common, and those that are become so through their diet. The now-extinct Carolina parakeet, for example, consumed cocklebur seeds, which contain toxins. (Audubon even portrayed several of these yellow-capped green birds on a bare twig, eagerly cracking such seeds in Birds of America.)

But like other birds still alive today, the Carolina parakeet might have grown into its poison, so to speak. (Indeed, Audubon also wrote of that species, “Their flesh is tolerable food, when they are young.”) For instance, Eurasian quails can cause nausea when consumed, but only if they’re captured at certain times of the year and along certain migratory paths.

Few birds, however, are consistently toxic, and the exceptions hail largely from Papua New Guinea.

New Guinea, with the village of Herowana below.

John Dumbacher

John Dumbacher, now a curator of birds at the California Academy of Sciences, stumbled on one of these species two decades ago while catching birds of paradise for his doctoral research. He’d spent the day running between mist nets clumped along a lush, slippery ridge—an area considered a “bird highway” by the locals because of the high numbers of birds flying through in the morning and evening.

Researchers use mist nets to catch birds, and they always capture more than they’re looking for. They also tend to get cut by the beaks and claws of birds that don’t appreciate being handled. Dumbacher remembers the first hint of toxin after working with a group of pitohuis, a bird indigenous to New Guinea. “After taking these pitohuis out of the net ... I licked my cuts, which were stinging, and ran to the next net. And then my mouth began to tingle and burn.”

At first Dumbacher assumed that the sensation came from mosquito repellant or a noxious plant. But another researcher had a similar experience a few days later. “I started thinking about it: I wonder if those birds are poisonous?” Dumbacher recalls. He then asked the local villagers about the bird, who said “’Ahh, that’s a rubbish bird. You can’t even eat that bird.’”

Suspension bridge in a New Guinean forest.

John Dumbacher

Feathers were passed about in camp after dinner, and although everyone agreed that feeling numb after touching a feather was unusual, no one thought it was important—that is, until the arrival of Bruce Beehler, who at the time was doing research as Scientific Assistant to the Secretary Emeritus, S. Dillon Ripley, of the Smithsonian Institution.

Dumbacher picked Beehler up at the airport. It was halfway to Varirata National Park when he told Beehler of the toxin, whereupon Beehler said, “’Stop the car, this is going to be the cover of Science,” remembers Dumbacher. "I said, ‘I don’t think so Bruce, but it is a cool story.’ He said, ‘Well, let’s go back to the capital, and we’ll get a little research permit so that we can collect tissue from them.’”

The poisonous bird of New Guinea did grace the cover of Scienceat the end of October 1992, about three years after Beehler and Dumbacher had first discussed the possibility. It had taken a few years to find a biochemist willing to test samples from the bird. John Daly of the National Institutes of Health accepted the project.

Daly found that skin samples taken from the pitohui were highly reactive with biological tissue. He eventually determined the poison to be homobatrachotoxin—the same chemical that, coincidentally, he had identified 20 years before as the substance that makes golden poison arrow frogs the most deadly in the world to humans. In other words, the birds from New Guinea and the frogs from South America had picked the same poison.

A blue-capped ifrita, another poisonous bird.

John Dumbacher

Dumbacher and his colleagues have since discovered another toxic bird genus—the blue-capped ifrita, which is common to the high cloudforests of New Guinea. They also discovered the source of the pitohui's toxin.

Years ago, Dumbacher had left vials and ethanol at Herowana village, where the Wildlife Conservation Society maintains a field site. His assistant returned to continue research, only to find 40 neatly labeled bottles containing various specimens, in the ethanol solution, of a small, predatory beetle, which the local residents had collected in the search effort for the toxin’s source. “This is something I’d never asked them to do,” Dumbacher says, but “having observed us do science in the field, they decided that this is how science must be done. ... It was really quite amazing.” Avit Wako, the primary collector, was included as an author on the paper describing the findings, which appeared in 2004 in the Proceedings of the National Academy of Sciences.

Analyses of the collections determined that this insect, called a melyrid beetle, was indeed the source of the toxin in the pitohui. “The beetles actually form a small portion of their diet, but it turns out that they are pretty loaded with poison,” says Dumbacher. “We estimate that it only takes a handful of these beetles—10 to 20—to give the pitohuis what they need.”

A melyrid beetle.

John Dumbacher

Melyrid beetles have “these weird vesicles on their sides,” according to Dumbacher. “No one has really figured out what they do, and we think that it is highly likely that they are producing poison or are a gland that stored poison.” Members of the same family of beetles exist in South America and are probably the source of the toxin in the golden frogs. (Other poisonous South American frogs from the same genus—Dendrobates—obtain some of their toxicity from ants. The batrachotoxin, however, is most likely a beetle phenomenon. For more on poisonous frogs, click here.

So far their venomous flesh and feathers have been ample armor for ifrita and especially pitohui populations. Without human predators, they thrive where other species cannot survive. But they do face another threat: The forests in New Guinea where they live are being cut down. Over a 15-year period ending in 2005, New Guinea lost more than 6.5 percent of its forest—an area about the size of New Jersey. “[Forests] are being removed for logging, [and] they’re being removed to make space for oil palm plantations,” explains Dumbacher. Because the melyrid beetle inhabits these forests, and because the pitohui's success may depend entirely on the success of the beetle, the bird’s future remains uncertain, according to Dumbacher. “If you are a brightly colored bird that is used to not flying away from predators, and all of the sudden your source of toxin disappears, you could be totally hosed.”